CiDRA Use of Foundation Fieldbus Protocol with SONARtrac Transmitters - Manual (Page 23)

Table 3 Transducer Block Configurations (Page 10)
SOS_MIN Float R/W
Minimum SOS value to search for. If too much energy
(such as from a high velocity vortical ridge) causes the
algorithms to calculate a sound speed below that of the
main SOS ridge* this parameter may need to be
increased. Care must be taken not to set this higher
than the expected minimum SOS for the application.
SOS_MAX Float R/W
Maximum SOS value to search for. If too much energy
along the 0 k value on the k-w plot and algorithms are
calculating SOS_MAX* even when SOS ridge indicates
an SOS below this value* may need to decrease this
parameter. Care must be taken not to set this lower
than the expected maximum SOS for the application.
SOS_MIN_QUALITY Float R/W
Minimum quality threshold for SOS/GVF display and
output.
SOS_CENTROID_WIDTH Float R/W Define width of peak to use in calculation of SOS.
SOS_FREQUENCY_THRESHOLD Float R/W
This value selects the threshold that the second
derivative of a power array (generated at a specific
frequency over all k-space values) must break in order
for the specific frequency point to be considered a valid
frequency point.
SOS_MIN_K Float R/W
This value sets the lower limit in k-space that is used in
the SOS auto frequency determination code. This value
is equal to the first k-space bin after 0: PI/deltaX/50
(there are 50 bins from 0 to PI/deltaX).
SOS_MAX_K Float R/W
This value sets the upper limit in k-space that is used in
the SOS auto frequency determination code. This value
is equal to the last k-space bin: PI/deltaX.
SOS_SEARCH_LIMIT Float R/W
This value is the +/- percentage of the estimated SOS
value (calculated using the auto frequency calculation
code) that determines the lower (Estimated SOS * 0.5)
and upper (Estimated SOS * 1.5) SOS search limits.
SOS_LAMBDA_DIAM Float R/W
Used to calculate the SOS dynamic frequency
maximum used when calculating SOS.SOS Max Freq =
(Max SOS search)/(Lambda Diameter * (Pipe
Diameter/12)).
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